Embodiments of the present invention relate to the evaluation of chamber components having textured coatings for substrate processing chambers.
A substrate processing chamber may be used to process a substrate with an energized process gas, such as a plasma. Typically, the process chamber comprises an enclosure wall that encloses a process zone into which a gas may be introduced, a gas energizer to energize a gas, and an exhaust to exhaust the gas. The process chamber may, for example, be used to deposit material on a substrate or etch material from a substrate. For example, the chamber may be used to sputter-etch material from a substrate or sputter-deposit material onto the substrate.
The chamber components exposed to the energized gas, such as for example, the sidewall or ceiling of the chamber, or the liner or focus ring about the substrate, are often coated with a textured coating to enhance the adhesion of the sputtered residues on the component. For example, a suitable chamber may be made from aluminum or quartz and coated with a plasma sprayed coating of aluminum oxide or alumino-silicate, as for example, described in commonly assigned U.S. Pat. No. 6,777,045, application Ser. No. 09/895,862 filed Jun. 27th, 2001, entitled A Chamber Having Components with Textured Surfaces and Method of Manufacture, A by Lin et al., which is incorporated herein by reference in its entirety. The coating enhances adhesion of residues which are formed in the chamber, such as for example, sputtering residues that are formed when the components are used in chambers in which a target is sputtered to deposit material onto a substrate. Without the coating, the residues that accumulate on the component over a number of process cycles, would eventually flake-off and fall upon and contaminate the substrate.
While chambers having the coated components generally provide better substrate yields and require less frequent chamber cleaning, sometimes, the sputtered residues accumulated on the coated component can cause the entire underlying coating to delaminate and peel-off the component. Such components are undesirable because they reduce the ultimate yield from the substrates being processed in the chamber due to contamination of the substrate by the peeled off coating flakes. However, current component fabrication and evaluation methods often fail to identify or separate those components that are able to withstand accumulation of the sputtered residues without delaminating from those components that cannot withstand excessive accumulate deposits.
Thus, it is desirable to have a method of fabricating and selecting chamber components having desirable coating characteristics. It is also desirable for the components to provide superior adhesion of process residues, such as sputtering residues, in a substrate processing chamber.